Grey sports coat can be fine with light brown pants, especially if you are blonde or blonde-brown, I think, but that cloth isn't perfect. The plaids should be larger, or better, the cloth should be a solid grey.

Perhaps we should step back and accept that there is no hard-and-fast rule on gray odd jackets. I think some folks categorically dislike light top/dark bottom, and that's what you're likely to end up with when you wear a gray odd jacket. You'll never persuade this bunch. Personally, I think there's no inherent problem there. gdl ably illustrates how to wear it. Of course, his moo shot probably works against his thesis...

In the case of brokencycle's fabric, my objection is that the colors seem spring-like, but it's a fall/winter fabric. Could be the photo, but that's my first reaction.